- Nov 28, 2006
- Reaction score
- Teesside, UK
Water contains minerals dissolved from the rock it passes over after it fell as rain. Some rocks, such as limestone and chalk, dissolve a lot and the water has a lot of calcium and magnesium dissolved in it - this is called hard water. Other rocks hardly dissolve at all so there is very little calcium and magnesium in it - this is called soft water.And what does soft water mean
If fish have evolved in hard water, their bodies can deal with lots of minerals but they suffer mineral depletion if kept in soft water. Fish which evolved in soft water get calcium deposits in their kidneys if kept in hard water.
Mollies are hard water fish which need a GH of at least 14 dH (or 250 ppm) and they are prone to disease if they are kept in water with a GH lower than that.